Varying-tone colour effects in synthetic fibre fabrics



United States Patent 3,356,444 VARYING-TONE COLOUR EFFECTS IN SYNTHETICFIBRE FABRICS Derek Haworth, Upper Cwmbran, Anil Chandrakant Parikh,Caerleon, and John Charles Turner, Ponthir, England, assignors toBritish Nylon Spinners Limited, Pontypool, England No Drawing. FiledFeb. 13, 1964, Ser. No. 344,536 Claims priority, application GreatBritain, Feb. 21, 1963, 6,949/63 2 Claims. (Cl. 821) ABSTRACT OF THEDISCLOSURE There is provided a dyed synthetic nylon fabric exhibitingvarying tone colour effects. The fabric is produced from a combinationof yarns having at least two different cross-sectional shapes and eachof the cross-sectional shapes having different proportions of titaniumdioxide therein.

The present invention concerns improvements in or relating tovarying-tone colour effects in synthetic fibre fabrics.

The colouring of fabrics can be effected either by dyeing the yarns orfibres from which they are made or by dyeing lengths of the fabricitself. The latter method is called piece dyeing; and it is the usualmethod employed when plain colours are acceptable, as in plain tuftedcarpet material.

Notwithstanding that piece dyeing is primarily a single colour process,it is known that pattern effects in piecedyed fabrics can be created bythe use of yarns which either accept colour differently from oneanother, by reason of having differing dye uptakes, or by reason of achemical dye-resist treatment having been applied to only some of theyarns, or which appear different in tone after dyeing by reason of thediffering light reflecting properties of the yarns used.

In our British patent specification No. 854,335 we have described how toproduce such pattern effects in piece-dyed carpet fabrics by employingsome nylon yarns the fibres of which had been heat-set as fibres andother nylon yarns the fibres of which had not been heat-set until spuninto yarns.

So far as nylon yarns and fibres are concerned, other methods ofproducing pattern effects in piece-dyed fabrics are resist processes inwhich, for instance, the amine ends of the nylon polymer chain areblocked in some of the yarns, and differential orientation processes inwhich some of the filaments are drawn to a different degree from theothers.

The above instanced resist process, however, limits the dyeing processto the use of anionic dyes. Effectively, too, the differentialorientation processes are limited to the use of sensitive kinds ofdyestuffs, such as certain acid and premetallised dyestuffs which aresensitive to rate of dyeing differences between yarns, which will tendto exaggerate any extraneous non-uniformities in the yarn.

We have now found a way of producing varying-tone colour effects inpiece-dyed synthetic fibre fabrics, especially nylon fabrics, whichenables distinctive tones to be produced without necessary limitation tothe use of dyestuffs of a special or critical nature.

According to the invention, a dyed, synthetic fibre fabric exhibitingvarying-tone colour effects contains a yarn or yarns composed ofsynthetic fibres and/or filaments, some of the said fibres or filamentsdiffering both as to their cross-sectional shape and their delustrantcontent from the others.

The yarns can be wholly of short, staple length fibres or wholly offilaments, or some of the yarns can be of such fibres and some offilaments. Alternatively, some or all of the yarns can be of both fibresand filaments, for instance of plied or core-spun type. Unless thecontrary is clear from the context of its use, the term fibres usedherein includes filaments.

In one form of the invention, two-tone colour effects are employed toproduce a visible pattern in the surface of the fabric, by using yarnsof one type in selected areas of the surface of the fabric and yarns ofanother type in the remainder of its surface.

The invention will now be described with particular reference to nylonpile fabrics of two-tone colour effects. The pile fabrics may be carpetfabrics of the type produced on so-called tufting machinery; and theyarns used may be bulked continuous filament yarns.

Two ends of such yarn, each of polyhexamethylene adipamide continuousfilaments and totalling some 3650 denier, are creeled alternately. Oneend of yarn is composed of so-called quarter dull filaments of tri-lobalcross-sectional shape; and the other end is composed of so-called brightfilaments of elliptical cross-sectional shape. The quarter dullfilaments have a titanium dioxide content of 0.2% by weight, and thebright filaments one of 0.03% by weight. The bright ellipticalcross-section filaments appear darker after dyeing than the quarter dulltri-lobal cross-section filaments; and disperse type dyestuffs can beemployed with satisfactorily distinctive results.

One end of yarn is tufted with a higher pile than the other in thoseareas where its colour tone is the one which is required to be visibleon the surface.

Instead of an elliptical cross-sectional shape, a circular cross-sectionis acceptable for the darker-toned filaments.

It is only with the combination of differing cross-sectional shape anddiffering de-lustrant content that an adequate two-tone effect can beproduced. For extra effect, it is of course, often desirable also tomodify the dye receptivity of one lot of fibres by a chemical dye-resistprocess or by increasing the number of basic dye sites available, or touse yarns with different extents of orientation (i.e. yarns the fibresof which have been drawn to different extents), and then use suitabledyestuffs to dye the fabric.

We have referred to a varying-tone colour effect, because the hue is notordinarily affected according to the invention. The difference in tonemay be due either to a difference in dye uptake or to a difference inthe lightreflecting properties of the yarns, or to a combination of thetwo.

Whilst carpet fabric has been exemplified above, it is to be stressedthat the dyed fabric may be of any structure, such as a woven or aknitted structure; and the varyingtone effect need not be in patternedareas, but may instead be, for instance, a two-tone effect in some orall of the yarns of the fabric.

We claim:

1. A dyed synthetic nylon fabric exhibiting varying tone colour effects,said fabric containing yarns of at least two different cross-sectionalshapes selected from tri-lobal, elliptical and circular, and each of theyarn of different cross-sectional shape containing titanium dioxide indifferent proportons.

2. A dyed, Synthetic fibre fabric exhibiting varying tone colour effectssaid fabric containing a first yarn of continuous filaments ofpolyhexamethylene adipamide having a titanium dioxide content of 0.2% byweight and having a tri-lobal cross-sectional shape and a second yarn ofcontinuous filaments of polyhexamethylene adipamide 3 4 having atitanium dioxide content of 0.03% by Weight OTHER REFERENCES and havinga circular cross-sectional shape. Moncrieff lvlamrlvmde Fibres, 4th ed1963, pp

R f d 609-610.

8 ereuces l e H. C. Speel, Textile Chemicals and Auxiliaries, 2nd ed.,UNITED STATES PATENTS 5 1957, p. 131.

2,278,888 4/1942 Lewis 8-14 X 3,033,240 5/1962 Bottorf 57 140 XR NORMANG. TORCHIN, Primary Examiner.

3,282,886 11/1966 Gadecki 8-55 X T. J. HERBERT, JR., Assistant Examiner.

1. A DYED SYNTHETIC NYLON FABRIC EXHIBITING VARYING TONE COLOUR EFFECTS,SAID FABRIC CONTAINING YARNS OF AT LEAST TWO DIFFERENT CROSS-SECTIONALSHAPES SELECTED FROM TRI-LOBAL, ELLIPTICAL AND CIRCULAR, AND EACH OF THEYARN OF DIFFERENT CROSS-SECTIONAL SHAPE CONTAINING TITANIUM DIOXIDE INDIFFERENT PROPORTONS.